TA×4
H. SagawaInstitute for Cosmic Ray Research
The University of Tokyofor Telescope Array collaboration
12014/10/13 H. Sagawa@UHECR2014
Outline
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Telescope Array (TA)
Recent TA results5- or 6-year data
Outline
2014/10/13 H. Sagawa@UHECR2014 3
Telescope Array (TA)
Recent TA results5- or 6- year data
TA×4extension
Telescope Array Collaboration
4
R.U. Abbasi1, M. Abe13, T.Abu-Zayyad1, M. Allen1, R. Anderson1, R. Azuma2, E. Barcikowski1, J.W. Belz1,D.R. Bergman1, S.A. Blake1, R. Cady1, M.J. Chae3, B.G. Cheon4, J. Chiba5, M. Chikawa6, W.R. Cho7, T. Fujii8,
M. Fukushima8,9, T. Goto10, W. Hanlon1, Y. Hayashi10, N. Hayashida11, K. Hibino11, K. Honda12, D. Ikeda8,N. Inoue13, T. Ishii12, R. Ishimori2, H. Ito14, D. Ivanov1, C.C.H. Jui1, K. Kadota16, F. Kakimoto2, O. Kalashev17,
K. Kasahara18, H. Kawai19, S. Kawakami10, S. Kawana13, K. Kawata8, E. Kido8, H.B. Kim4, J.H. Kim1, J.H. Kim25, S. Kitamura2, Y. Kitamura2, V. Kuzmin17, Y.J. Kwon7, J. Lan1, S.I. Lim3, J.P. Lundquist1, K. Machida12, K. Martens9,
T. Matsuda20, T. Matsuyama10, J.N. Matthews1, M. Minamino10, K. Mukai12, I. Myers1, K. Nagasawa13, S. Nagataki14, T. Nakamura21, T. Nonaka8, A. Nozato6, S. Ogio10, J. Ogura2, M. Ohnishi8, H. Ohoka8, K. Oki8, T. Okuda22, M. Ono14, A. Oshima10, S. Ozawa18, I.H. Park23, M.S. Pshirkov24, D.C. Rodriguez1, G. Rubtsov17,
D. Ryu25, H. Sagawa8, N. Sakurai10, A.L. Sampson1, L.M. Scott15, P.D. Shah1, F. Shibata12, T. Shibata8, H. Shimodaira8, B.K. Shin4, J.D. Smith1, P. Sokolsky1, R.W. Springer1, B.T. Stokes1, S.R. Stratton1,15, T.A. Stroman1,
T. Suzawa13, M. Takamura5, M. Takeda8, R. Takeishi8, A. Taketa26,M. Takita8, Y. Tameda11, H. Tanaka10, K. Tanaka27, M. Tanaka20, S.B. Thomas1, G.B. Thomson1, P. Tinyakov17,24, I. Tkachev17, H. Tokuno2, T. Tomida28,
S. Troitsky17, Y. Tsunesada2, K. Tsutsumi2, Y. Uchihori29, S. Udo11, F. Urban24, G. Vasiloff1, T. Wong1, R. Yamane10, H. Yamaoka20, K. Yamazaki10, J. Yang3, K. Yashiro5, Y. Yoneda10, S. Yoshida19, H. Yoshii30, R. Zollinger1, Z. Zundel1
1 University of Utah 2 Tokyo Institute of Technology 3 Ewha Womans University 4 Hanyang University5 Tokyo University of Science 6 Kinki University 7 Yonsei University 8 ICRR, University of Tokyo
9 IPMU, the University of Tokyo 10 Osaka City University 11 Kanagawa University 12 University of Yamanashi13 Saitama University 14 Astrophysical Big Bang Laboratory RIKEN, Wako 15 Rutgers University
16 Tokyo City University17 INR of the Russian Academy of Sciences 18 Waseda University19 Chiba University 20 KEK 21 Kochi University 22 Ritsumeikan University 23 Sungkyunkwan University
24 Universite de Libre de Bruxelles 25 Ulsan National Institute of Science and Technology26 ERI, University of Tokyo 27 Hiroshima City University 28 Advanced Science Institute, RIKEN
29 National Institute of Radiological Science 30 Ehime University
5 countries, 126 researchers
2014/10/13 H. Sagawa@UHECR2014
Telescope Array detector
32km
Utah, USA- lat. 39.30°N, long. 112.91°W
28km
5
Fluorescence Detector (FD)
Elevation angle:3~33°
Surface Detector (SD)3m2 scintillator detector507SDs, 、1.2km spacing~700km2
2014/10/13 H. Sagawa@UHECR2014
Hybrid observation since Mar, 2008
Refurbished HiRes
Recent TA results
Anisotropy (hot spot)Mass composition (Xmax)
Energy spectrum
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Anisotropy of arrival directions of highest-energy cosmic rays (hotspot)
• TA SD data 5 years (2008/May ~ 2013/May)
• E > 5.7×1019eV以上, zenith angle < 55°:72 events
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distribution of arrival directions (blue points)
TA FoV(Dec. > -10°)
Equatorial coordinates
GC
HotspotAnisotropy of highest-energy cosmic rays
• Maximum significance• direction:R.A. = 146.7°, Dec. = 43.2°• observed:19 (19/72=26%)• Expected for isotropy:4.5 (4.5/72=6%)• Li-Ma significance: 5.1𝜎𝜎
• Chance probability to obtain maximum significance of 5.1𝜎𝜎:3.7x10-4 (3.4𝜎𝜎)
• MC:15, 20, 25, 30, 35°-radius circles
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oversampling using 20-degree radius circles
Significance map
5-year data
ApJ 790, L21 (2014)
Hotspot +1-year data
• 2008/May ~ 2014/May (6 years)
• E > 5.7x1019eV: 72 events→87 events(+15)• Hotspot : 19events→23 events( +4)• Max. Li-Ma significance: 5.1𝜎𝜎 →5.55𝜎𝜎 Chance prob. = 3.4𝜎𝜎 →4.0𝜎𝜎2014/10/13 H. Sagawa@UHECR2014 9
Arrival direction distribution Significance map
blue:5-year datared: recent 1-year data
D.BergmanCOSPAR 2014
(19/72~26%, 4/15~26%)5 yrs +1 yr
(3.1x10-5)
Compatibility with isotropy
• Autocorrelation p ~ 0.001 (δ ~ 20o – 25o)• AGN p ~ 0.007• LSS p ~ 0.001
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Xmax analysis by hybrid events• MD FD: [refurbished HiRes] + SD
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J.N.MatthewsQui Nhon 2014arXiv:1408.1726Submitted to APP
(MD FD + SD)
hybrid
H. Sagawa@UHECR2014consistent with a light, largely protonic composition
Black points:TA dataMC(QGSJET-II-03)
blue:Proton, red:Fe18.2 < log10(E/eV) < 18.4
log10(E/eV) > 19
TA energy spectrum
• SD data:2008/May~2014/May (6 years)
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18.70±0.02
19.74±0.04ankleCutoff consistent with GZK cutoff
E > 1019.8eVExpected (no cutoff) = 85.93observed = 32Cutoff chance prob. = 6.59𝜎𝜎
D.BergmanCOSPAR 2014
Model of extremely-high-energy cosmic rays
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Extragalactic proton CR
Distribution cases• isotropic• LSS (2MASS < 250 Mpc) Evolution (1+z)m
Injection spectrum E-P
source
Energy scale Flux normalization factor
4 fit parameters
Propagation code• Kalashev + Kido, arXiv:1406.0735Photon background• CMB• IRBNo GMF and no extra GMF
propagation
z ≲ 0.7○ 5-year TA SD data
If GZK cutoff exists,sources of highest-energy CRs whicharrive at the earth are restricted to nearby objests
Ursa Major cluster(D=20Mpc)
Virgo cluster(D=20Mpc)
2MASS catalog John P. Huchra, et al 2012, ApJ, 199, 26+ TA 5-year significance (color map)
Nearby galaxies(within ~50 Mpc)
14
Distribution of galaxies: anisotropic
Anisotropy of arrival directions ofhighest-energy cosmic rays2014/10/13 H. Sagawa@UHECR2014
• Quadrule TA SD (~3000 km2)• 500 scintillator SDs
2.1 km spacing (Japan)
• 2 FD stations each with 10 refurbished HiRes telescopes (US)
• Apply grants this fall (Japan, US)+ from Korea, Russia
• 2-year construction• 3-year observation
• TA SD: 21 year data• TA hybrid: 18 year data
TA×4 proposal
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Efficiency for additional TA×4 SD array
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TA SD reconstructionefficiency =100% forE > 1019eV
Differential for energiesTrigger condition. 3 MIPS. 3-fold SDs. < 8x2.08/1.2usec
Reconstruction. NSD≥ 4
57 EeV
Trig+recon
Trig. eff
Prospect of TA×4
• Arrival direction• Hotspot
• Confirmation at > 5𝜎𝜎 level• Fine structure?• Other excess spots?• Study of galactic MF and extragalactic MF
• Point source search• Correlation with the results by other experiments
• TA/Auger whole sky analysis• Search for correlation with gamma-ray sources• Search for correlation with IceCube neutrinos
• Measurement of spectrum and Xmax of cosmic rays around cutoff with high statistics
• Search for UHE gamma rays and neutrinos
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Arrival directions of TA 6-year data
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Prospect of TA×4
• Arrival direction• Hotspot
• Confirmation at > 5𝜎𝜎 level• Fine structure?• Other excess spots?• Study of galactic MF and extragalactic MF
• Point source search• Correlation with the results by other experiments
• TA/Auger whole sky analysis• Search for correlation with gamma-ray sources• Search for correlation with IceCube neutrinos
• Measurement of spectrum and Xmax of cosmic rays around cutoff with high statistics
• Search for UHE gamma rays and neutrinos
192014/10/13 H. Sagawa@UHECR2014
Ursa Major Cluster(D=20Mpc)
Virgo Cluster(D=20Mpc)
2MASS catalog velocity 0 – 3000 km/sJohn P. Huchra, et al 2012, ApJ, 199, 26+ 5-year TA data (Color contour)
Nearby Galaxy Clusters and hotspotPerseus-Pisces
Supercluster(D=70Mpc)
Heliocentric velocity (Rough Distance)Red: 0-1000km/s (D = 0-15Mpc)Blue: 1000-2000km/s (D = 15-30Mpc) Green: 2000-3000km/s (D = 30-45Mpc)
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2014/10/13 H. Sagawa@UHECR2014
Prospect of TA×4
• Arrival direction• Hotspot
• Confirmation at > 5𝜎𝜎 level• Fine structure?• Other excess spots?• Study of galactic MF and extragalactic MF
• Point source search• Correlation with the results by other experiments
• TA/Auger whole sky analysis• Search for correlation with gamma-ray sources• Search for correlation with IceCube neutrinos
• Measurement of spectrum and Xmax of cosmic rays around cutoff with high statistics
• Search for UHE gamma rays and neutrinos
212014/10/13 H. Sagawa@UHECR2014
Galactic filaments?
Ursa Major Cluster(D=20Mpc)
Virgo Cluster(D=20Mpc)
2MASS catalog velocity 0 – 3000 km/sJohn P. Huchra, et al 2012, ApJ, 199, 26+ 5-year TA data (Color contour)
Nearby Galaxy Clusters and hotspotPerseus-Pisces
Supercluster(D=70Mpc)
Heliocentric velocity (Rough Distance)Red: 0-1000km/s (D = 0-15Mpc)Blue: 1000-2000km/s (D = 15-30Mpc) Green: 2000-3000km/s (D = 30-45Mpc)
22
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Prospect of TA×4
• Arrival direction• Hotspot
• Confirmation at > 5𝜎𝜎 level• Fine structure?• Other excess spots?• Study of galactic MF and extragalactic MF
• Point source search• Correlation with the results by other experiments
• TA/Auger whole sky analysis• Search for correlation with gamma-ray sources • Search for correlation with IceCube neutrinos
• Measurement of spectrum and Xmax of cosmic rays around cutoff with high statistics
• Search for UHE gamma rays and neutrinos
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Search for clusters of highest energy cosmic rays
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TA: 2008/May – 2013/May (5 yrs) 72 events [ApJ 790 (2014) L21]Auger: 2004/Jan – 2009/Dec (5.5yrs) 62 events [APP 34 (2010) 314]
Hint of a point source?
Auger 123 EeV
TA 136 EeV
TA 101 EeV
E > 5.7x1019eV
doublet
new event
Prospect of TA×4
• Arrival direction• Hotspot
• Confirmation at > 5𝜎𝜎 level• Fine structure?• Other excess spots?• Study of galactic MF and extragalactic MF
• Point source search• Correlation with the results by other experiments
• TA/Auger whole sky analysis• Search for correlation with gamma-ray sources • Search for correlation with IceCube neutrinos
• Measurement of spectrum and Xmax of cosmic rays around cutoff with high statistics
• Search for UHE gamma rays and neutrinos
252014/10/13 H. Sagawa@UHECR2014
26
TA Hotspot5.1σ
Auger ∼3σ around Cen A
TA and Auger pretrial significance summed over with 20o-radius Circle
Adopted same analysis as the TA
2014/10/13 H. Sagawa@UHECR2014
Prospect of TA×4
• Arrival direction• Hotspot
• Confirmation at > 5𝜎𝜎 level• Fine structure?• Other excess spots?• Study of galactic MF and extragalactic MF
• Point source search• Correlation with the results by other experiments
• TA/Auger whole sky analysis• Search for correlation with gamma-ray sources • Search for correlation with IceCube neutrinos
• Measurement of spectrum and Xmax of cosmic rays around cutoff with high statistics
• Search for UHE gamma rays and neutrinos
272014/10/13 H. Sagawa@UHECR2014
Prospect in the summer of 2020
If we start TAx4 project in 2015,2015-2016 construction of new detectors
2017-2019 operation of full TAx4
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Arrival directions of TA 6-year data
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1 cluster in the hotspotin the summer of 2020
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2 clusters in the hotspot in the summer of 2020
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2 clusters in the hotspot+Perseus cluster in the summer of 2020
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Prospect of TA×4
• Arrival direction• Hotspot
• Confirmation at > 5𝜎𝜎 level• Fine structure?• Other excess spots?• Study of galactic MF and extragalactic MF
• Point source search• Correlation with the results by other experiments
• TA/Auger whole sky analysis• Search for correlation with gamma-ray sources • Search for correlation with IceCube neutrinos
• Measurement of spectrum and Xmax of cosmic rays around cutoff with high statistics
• Search for UHE gamma rays and neutrinos
332014/10/13 H. Sagawa@UHECR2014
TA and Auger energy spectrum
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Spectrum by TA SD for 6 years (this conf.)
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Spectrum by TA SD for 7 years in the summer of 2015
Spectrum only by TA SD for 12 years in the summer of 2020
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Spectrum by (TA SD for 9 years and TAx4 for 3 years) in the summer of 2020
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Spectrum by (TA SD for 9 years and TAx4 for 3 years)together with other cases
in the summer of 2020
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Prospect of TA×4
• Arrival direction• Hotspot
• Confirmation at > 5𝜎𝜎 level• Fine structure?• Other excess spots?• Study of galactic MF and extragalactic MF
• Point source search• Correlation with the results by other experiments
• TA/Auger whole sky analysis• Search for correlation with gamma-ray sources • Search for correlation with IceCube neutrinos
• Measurement of spectrum and Xmax of cosmic rays around cutoff with high statistics
• Search for UHE gamma rays and neutrinos
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Xmax for TA hybrid events for 9 years and TAx4hybrid events for 3 years
(assuming proton QGSJET II-03 model)
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TA hybrid events for corresponding to 18-year TA hybrid events
Prospect of TA×4
• Arrival direction• Hotspot
• Confirmation at > 5𝜎𝜎 level• Fine structure?• Other excess spots?• Study of galactic MF and extragalactic MF
• Point source search• Correlation with the results by other experiments
• TA/Auger whole sky analysis• Search for correlation with gamma-ray sources by MAGIC etc.• Search for correlation with IceCube neutrinos
• Measurement of spectrum and Xmax of cosmic rays above cutoff with high statistics
• Search for UHE gamma rays and neutrinos
422014/10/13 H. Sagawa@UHECR2014
Summary
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TA
Hotspot: anisotropy ofcosmic rays with E >
5.7×1019eV (post-trial 4σ)
consistent with a light, largely protonic composition
(E > 1018.2eV)
Spectrum breaks consistent with
GZK cutoff (6.6σ)e+e- production dip
TA×4Quadruple TA SD
2 more FDs
Nearby extragalactic universe exploring by highest-energy
cosmic rays5- or 6-year data
END
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TALE+TA spectrum (E > 1015.9 eV)
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Energy region over > 4 decades
TALE Ckov: Cherenkov component is major
(FD) (SD)
Breaks at around 1016.2eV and 1017.3eV
H. Sagawa@UHECR2014
TA: 6 year SD dataTALEObservation time:144 hours(2013/Sep/6 ~ 2013/Dec/6)
Statistical test for compatibility with LSS and isotropy
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Correlation with AGN from VCV catalog
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6-year TA SD datazenith angles < 45°
Galactic coordinates● : AGN: ●: TA events correlating within 3.1°○: non-correlating events
Ntot = 53, Ncor = 21, (40%)Nbg = 12.5 (24%)p-value = 0.007 (2.7𝜎𝜎)
Correlation with AGN from VCV catalog
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